"The skin is the largest organ in the body - it protects us. Holds us together. Literally lets us know what we are feeling. The skin can be soft and vulnerable. Highly sensitive, easy to break. Skin doesn't matter to a surgeon. We will cut right through it, go inside, find out the secrets underneath. It takes delicacy and sensitivity... No matter how thick-skinned we try to be, there's millions of electrifying nerve endings in there. Open and exposed and feeling way too much. Try as we might to keep from feeling pain, sometimes it's just unavoidable. Sometimes that's the only thing left - just feeling."
... Grey's Anatomy, Season 6: How Insensitive